As an example of the use of a nanoscale light spot smaller than an optical diffraction limit, thermally assisted magnetic recording, which uses the near-field light as a light source for increasing temperature of a magnetic recording medium (refer to Patent documents 1 to 4), is suggested.
Moreover, thanks to recent advances in semiconductor microfabrication technology, nanoscale quantum dots have drawn attention in the communication network field, wherein the nanoscale quantum dots use ultimate particle property by controlling a single electron with quantum mechanical effects. For example, following technologies are suggested, a manufacturing method for appropriately controlling the size of quantum dots (refer to Patent document 5), and a near-field concentrator using multi-layered quantum dots (refer to Patent document 6).